>For example, Dutch kindergarten children performed worse than English children on a task that required them to roughly add together two-digit numbers. This was despite the fact they were slightly older and had better working memory, because Dutch kindergarten starts later than in the UK. But on nearly every other metric, including counting ability, roughly adding and comparing quantities of dots, and simple addition of single-digit numbers, the two groups performed at the same level.
This is rather surprising. I would have guessed that adding numbers verbalized in little endian order would be easier because it makes carryover much more natural.